The risk of a transformer causing a fire is low, but not negligible and the consequences can be very severe if it does occur. The aim of this paper is to promote “Good Fire Safety Practices”. It endeavors to do this by:

1. Discussing Fire Physics and Typical Transformer Fire Scenarios. 
2. Presenting typical transformer fire scenarios. 
3. Discussing Nitrogen Injection Fire Prevention System (NIFPS) which reduce the risk and cons equences of a transformer fire. 
4. To present practical and cost effective strategies for fire prevention and for control and risk mitigation measures which can be applied to both transformers and transformer installations.

Extinguishment Of Fires

Fire is the common term for combustion which is the chemical reaction of oxidation, which happens when for example the organic compounds (Mineral oil in case of transformer) are combined with oxygen in air at a high temperature. The combustion is made up from a large number of chemical reactions in many steps. 

1. Remove the Heat (Cooling) 
2. Oxygen displacement or dilution (Smothering) 
3. Removal of fuel (Starvation) 
4. Ease of installation (easier handling with lighter equipment and labour at the job site) 
5. Resistance to Seismic Shock

On receipt of all activating signals, the system drain pre-determined volume of hot oil from the top of tank (i.e. top oil layer), through outlet valve, to reduce tank pressure by removing top oil and simultaneou sly injecting nitrogen gas at high pressure for stirring the oil at pre-fixed rate and thus bringing the temperature of top oil layer down. Transformer conservator isolation valve blocks the flow of oil from conservator tank in case of tank rupture / explosion or bushing bursting. Nitrogen occupies the space created by oil drained out and acts as an insulating layer over oil in the tank and thus preventing aggravation of fire.